H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems

H04Q2213/13541—Indexing scheme relating to selecting arrangements in general and for multiplex systems routing

H—ELECTRICITY

H04—ELECTRIC COMMUNICATION TECHNIQUE

H04Q—SELECTING

H04Q3/00—Selecting arrangements

H04Q3/72—Finding out and indicating number of calling subscriber

Description

Background of the Invention

This invention is directed to a telecommunication network in
which a telecommunication switch provides subscribers with call
related features. More specifically, the invention is directed to
the selection of the specific calling features which are made
available to a calling party.

The prior art document US5436957 discloses that a telecommunication switch of the program controlled type is
capable of providing a variety of call related features, such as
speed dialing, three-way calling, conference calling, etc., for
subscribers served by the switch. Typically, a service provider
will provide a charge for each call feature or group of call
features provided to a subscriber. The subscriber may elect a
feature or set of features to be provided by the switch. The
selection of features by the subscriber is normally stored in the
local switch which serves the subscriber. Thus, features are made
available based on the particular subscriber's line from which calls
originate, as opposed to the person making the call.

Various features and capabilities are provided subscribers by
local and long distance service providers. For example, a long
distance or toll service provider may issue a credit card to a
subscriber permitting long distance calls to be charged to an
account associated with the credit card. Typically, an
authorization code must be entered by the subscriber in order to be
recognized as a valid user of the credit card. It is well known
that this is utilized to minimize the fraudulent obtaining of
services by those not authorized to make charges to an account.
Normally, the entry of the account number and the authorization code
causes the service provider to provide the subscriber with a set of
predetermined calling features that are not related to the point of
origin of the originating call, i.e. unrelated to the local line
used by the calling party.

In many situations it is desirable to allocate call features
based on the specific line of the originating call. In a company
having a substantial number of employees, different sets of
employees may be given different call privileges based on the
telephone line assigned to each employee. For example, only a
select group of employees normally required to make international
calls may be provided with certain features (access to international
dialing). Should an employee with such privileges desire to place
an international call from a telephone line which does not have
international calling privileges, a problem exists.

A local system, such as a PBX or Centrex system, may permit
the use of an authorization code by individual subscribers to
"unlock" certain calling privileges. In this situation, the
subscriber is given access to a feature package based only on the
unlocked call features. Thus, there exists a need for greater
flexibility in the control of access to call features.

Summary of the Invention

An object of the present invention is to provide a solution to
this need by providing a technique which permits call features to be
made available based upon a combination of factors, such as the
telephone line from which the call originates and a personal
identification number (PIN) associated with the individual making
the call. The invention is defined by the independent claims 1 and 5.

In an illustrative method in accordance with the present
invention, a telecommunication network includes a second
telecommunication switch that supports subscribers coupled to a
first switch. The first switch recognizes a call origination
request for services to be provided by the second switch by a
calling party on an associated communication line. A first record
in a database coupled to a second switch is located based upon the
identification of the calling party's line. The second switch is
disposed at a hierarchical level above the first switch. A first
set of predetermined features is determined based upon information
contained in the first record. A PIN is entered by the calling
party and a second record is located in a database coupled to the
second switch based upon the PIN. The second record is independent
of the first record. A second set of predetermined features is
determined based upon information contained in the second record. A
final set of features to be provided to the calling party is based
upon a combination of the features defined by the first and second
sets of features. Thus, features associated with a particular line
are supplemented by other features associated with a particular
subscriber's PIN.

Brief Description of the Drawing

FIG. 1 is a block diagram of a telecommunication network which
incorporates an embodiment of the present invention.

Detailed Description

FIG. 1 illustrates a telecommunication network in which local
access and transport areas (LATA) support communications among
subscribers located in the LATAs. Communications between the LATAs
are provided by switches associated with the toll switching system.

The LATA 10 which may be located in the Chicago, Illinois area
serves a plurality of subscribers including a business subscriber
associated with customer premises equipment (CPE) 12 which may
typically consist of a telephone set. However, it will be
understood that CPE may consist of various equipment suited for the
transmission of data as well as voice communications. The CPE 12 is
directly supported by a private branch exchange (PBX) 14 which may
comprise an AT&T PBX such as the Definity®. The PBX 14 supports a
plurality of CPE equipment (not shown) directly coupled to the PBX.
A central office switch 16 such as an AT&T 5ESS® switch supports
communications from the business subscribers associated with PBX 14
via trunk lines 18 connected between the PBX and the switch. It
will be understood that other subscribers can also be directly
served by switch 16.

Additional subscribers, for example the subscriber associated
with CPE 20, within LATA 10 are supported by central office switch
22. The subscriber associated with CPE 20 may be a residential
telephone user or a general member of the public served by a
telephone. Another class of subscribers, e.g. a business user
associated with CPE 24, are supported by Centrex service equipment
26 associated with central office switch 22. These subscribers
typically represent groups of business customers or other groups
which desire common calling features among related members which are
supported by Centrex services. Although, subscribers served by a
PBX or Centrex services may be provided with similar features and
capabilities, differences in the implementation of such services
often limits the use of the features to other members directly
served by the same PBX/Centrex equipment. Switches 16 and 22 may
comprise program controlled switches such as the AT&T 5ESS® Switch.

An inter-exchange carrier (IXC) switch 28 supports
communications with central office switch 16 by trunk lines 30 and
central office 22 via trunk lines 32. An inter-exchange carrier
provides what is commonly referred to as long distance service and
may consist of a carrier such as AT&T Corp. Such carriers provide
interLATA communication services. The IXC switch, which may
comprise an AT&T 5ESS® switch, functions as an edge or point of
contact switch with communications from LATA 10. It will be
understood by those skilled in the art that switches 16 and 22 will
also have trunk communication channels with other intraLATA and
interLATA switches. A service control point (SCP) database 34 is
coupled to switch 28 by communication lines 36. In accordance with
an embodiment of the present invention, the SCP 34 stores a
plurality of records corresponding to subscribers served by LATA 10.
The records contain individual subscriber data relating to call
features and could contain the type of CPE used.

The LATA 54 includes a central office switch 56 which is
connected by trunk communication lines 58 with IXC switch 48. The
switch 56, which may comprise an AT&T 5ESS® switch, provides direct
subscriber services to residential subscribers, for example a
subscriber associated with CPE 60. The switch 56 also provides
Centrex services 62 to subscribers, such as the subscriber
associated with CPE 64. Central office switch 66 is connected by
trunk communication lines 68 with IXC switch 48. PBX 70 is
connected by trunk communication lines 72 to switch 66 and supports
subscribers such as a business subscriber associated with CPE 74.
Switches 56 and 66 are similar to switches 22 and 16. Groups of
affiliated business subscribers may be supported by the Centrex or
PBX facilities.

The network shown in Figure 1 is simplified in order to more
clearly illustrate the embodiments of the invention. It will be
apparent to those skilled in the art that other non-illustrated
elements are present and operate to perform known functions. For
example, signal transfer points (STPs) are used to transmit data and
command information among the switches and databases (SCPs) using
data transmission links as is known in signaling system 7. In a
high reliability network the STPs and SCPs are deployed in duplicate
pairs so that one pair is available in the case the other pair
becomes unavailable such as during an unexpected failure or while
maintenance is being performed. The shown communication trunk lines
between switches are actually two sets of communication links: one
for user information such as voice and the other for the
transmission of control messages and data between the switches. Not
shown are STPs associated with each switch and database; the STPs
facilitate the communication of the control data on the separate
links.

In accordance with the present invention IXC switch 28 is
capable of providing a point of access interaction by trunk lines 30
and 32 to subscribers served directly or indirectly by central
office switches 16 and 22. Similarly, IXC switch 48 provides by
trunk lines 58 and 68, a point of access interaction with
subscribers served directly or indirectly by central office switches
56 and 66. "Point of access" capability of the IXC switches means
that these switches have the capability of servicing incoming call
requests like a local central office switch. Further details
describing the utilization of this capability to provide features in
accordance with the present invention are described below with
regard to examples of call handling by the network.

As shown in FIG. 1, SCP databases 34 and 50 contain records
relating to individual subscribers served by LATAs 10 and 54,
respectively. Table 1 illustrates exemplary records stored in these
SCP databases. The records associated with CPE 60, 64 and 74 are
stored in SCP database 50; the other exemplary records shown in
Table 1 are stored in SCP database 34. Each record includes data
defining features and CPE type. The record identified with
subscriber "PIN(X)" indicates a record identified solely by a
personal identification number X as opposed to the other subscriber
records shown in Table 1 which are associated with specific CPEs.

Referring to Table 1, a record exists for subscriber 24 which
includes data that has predefined features and CPE type. It will be
understood that subscribers identified by reference numbers are
subscribers associated with the CPE of the same reference number.
Typically, records stored in SCP database 34 are located by
reference to a predetermined directory number assigned to the
subscriber. It will be well known to those skilled in the art that
the calling party's directory number can be automatically generated
by the supporting central office switch and forwarded to the IXC
switch with the call initiation request, such as by utilizing the
known signaling system 7 (SS7). This permits the IXC switch to
locate the corresponding record in the SCP database.

Referring to Table 1, subscriber 24 has a stored directory
number of 312-713-1234 and a predetermined set of features. One
feature includes an individualized dial plan (IDP1), also known in
telephony as a custom or customized dial plan. The IDP1 defines a
business group (BG) dial plan utilized in making business calls and
abbreviated called dialing information such as the prefixes, if any,
and number of digits associated with extension-only dialing of
another business group subscriber. For example, the IDP1 may define
that a five digit number constitutes a BG extension if a
predetermined leading digit(s) is used.

Another group of features is associated with terminal group
and station restrictions (TGSR). The illustrative TGSR features
include the definition of a terminal group identification (TGID) of
05 (an intraswitch identification of business group), and further
defines business group restrictions associated with subscriber 24 as
being a semi-restricted originating (SRO) and unrestricted
terminating (URT) permissions. A semi-restricted originating
permission restricts the directory numbers which can be called by
the subscriber. For example, a subscriber may be limited to
directory numbers associated only with his business group or company
or to a predetermined local group of directory numbers, so as to
restrict toll dialing. With regard to receiving or terminating a
call, subscriber 24 is designated as an unrestricted terminating
permission indicating that this subscriber can receive all calls
without restriction, that is, without limitations.

A multi-switch business group (MBG) feature includes an
identification number (MBGID), e.g. an MBGID of 10. This
identification can be used across switches to classify related
groups of subscribers such as members of the same company which can
be used for call control purposes. The CPE type of subscriber 24 is
defined as analog with dual-tone multifrequency (DTMF) signaling
capability. This defines the type of CPE equipment associated with
the stored directory number of subscriber 24. In view of this
illustrative set of features for subscriber 24, it will be apparent
that some forms of signaling typically utilized from a CPE to a
supporting switch is not utilized by any of the defined features.
For example, a flash-hook signal is not needed to activate any
feature associated with subscriber 24, and hence would not be
recognized by IXC switch 28. However, a flash-hook signal may be
recognized by the intermediate central office switch 22 or the
related Centrex equipment 26 which are also capable of serving
subscriber 24.

The record associated with subscriber 12 as shown in Table 1
is similar to the record associated with subscriber 24. Differences
between the records include a different directory number, a
different terminal group identification (06 rather than 05) and an
unrestricted origination (URO) restriction as opposed to a semi-restricted
origination (SRO) restriction for subscriber 24. The
unrestricted origination indicates that subscriber 12 has no
restrictions on the calls which can be made, i.e. any directory
number can be dialed and processed as a valid call request. An SRO
restriction would limit the subscriber to call originations to only
members of the same BG. It will be noted that subscriber 12 has the
same MBGID(10) indicating a common organization or company
affiliation with subscriber 24. The CPE type for subscriber 12 is a
custom integrated services digital network (ISDN) terminal.

Subscriber 20 has a null entry for features, indicating that
this subscriber is to be treated as a plain old telephone service
(POTS) type of service. The CPE type is defined as an analog DTMF
terminal. The analog CPE type indicates that analog signaling can
be originated and received as opposed to the ISDN CPE type
associated with subscriber 12 which uses digital signaling using the
data or D-channel associated with ISDN lines. Alternatively, no
entry (record) for subscriber 20 would be required if a default
condition of POTS is assumed for subscribers without records.

A subscriber identified as PIN(X) has a record stored in SCP
database 34 but is not associated with a predetermined CPE. The
PIN(X) subscriber record is retrieved by a caller entering a
personal identification number from any CPE. The features
associated with this subscriber are generally similar to the
features described with regard to subscriber 12, but does not
contain a terminal group identification parameter. However, the
PIN(X) subscriber includes an additional feature of "3-WAY"
indicating that this subscriber is allowed to make 3-way calls.
Since a flash-hook signal, or the equivalent of the flash-hook
signal if implemented in ISDN signaling, is utilized for 3-way call
signaling, a flash-hook signal will have meaning to and be acted
upon by IXC switch 28 during a call involving the PIN(X) subscriber.
The CPE type is indicated as "NULL" since the type of CPE equipment
which may be utilized by the subscriber is not known.

Table 1 is an example of certain records stored within SCP
database 34 in accordance with the present invention. Likewise,
stored within this database will be subscriber records associated
with features and CPE types for other CPE associated subscribers and
PIN identified subscribers within LATA 10.

As shown in Table 1, subscribers 60 and 64 include similar
features and CPE definitions as described above. However, it will
be noted that these subscribers are supported by IXC switch 48 and
hence, their records are stored in the associated SCP database 50.
These records are shown in Table 1 for convenience and to enable
comparisons to be easily made. The features associated with
subscriber 64 are similar to that previously described for
subscriber 24 except that the terminal group identification for
subscriber 64 is 15 (as opposed to 5 for subscriber 24). It will be
further noted that the CPE type for subscriber 64 is a national ISDN
(N-ISDN) terminal type. It will be noted that subscribers 12, 24,
64, and PIN(X) are members of the same multiple switch business
group as indicated by the same MBGID identification.

In accordance with the embodiments of the present invention,
the IXC switch provides features and services that traditionally are
provided by a PBX, Centrex, or central office which directly serves
the subscribers. Groups of subscribers, such as geographically
separated groups of employees of the same corporation, which are
served by different PBXs, Centrex equipment, or central offices in
different LATAs, can be treated as a common business group for
purposes of communication services, and can be provided access to
the same dialing plan, features, and services. This constitutes an
advantage in that it makes the operation of the telephone services
seem the same for the different groups of subscribers.

Call Scenario #1

In this example subscriber 24 makes a call to subscriber 12.
The IXC switch 28 provides primary handling of the call even though
neither the originating subscriber 24 nor the terminating subscriber
12 are supported directly by switch 28. Since IXC switch 28
provides the primary call processing, enhanced subscriber features
can be supported, such as on-network (abbreviated) dialing, even
though subscriber 24 is supported by Centrex 26 and subscriber 12 is
supported by PBX 14. It will be noted by those skilled in the art
that in a conventional system a subscriber supported by Centrex
features of a central office switch would not be able to utilize
Centrex features such as on-network (abbreviated) dialing except
with other subscribers supported by the same Centrex facility. It
is similarly true that subscribers traditionally served by a PBX
could not utilize such features except with other subscribers
supported by the same PBX.

Subscriber 24 goes off-hook and receives dial tone via Centrex
26 and central office switch 22. In this illustrative example,
subscriber 24 then dials an access code followed by the
abbreviated number for destination subscriber 12. Trunk 32 could be
a trunk sharing public traffic (public trunk) or it could be a
private dedicated trunk (private trunk). Call processing is
discussed for each of these two types of trunks.

Assume in a first example that trunk 32 is a public trunk.
Subscriber 24 dials an access code, such as *10288, followed by
the abbreviated digits for the called party. The access code
digits "*10" inform switch 22 that an alternate carrier is
being requested to provide services to the subscriber. The
access code digits "288" inform switch 22 that the alternate
carrier to provide the services is AT&T. In response to the
receipt of the access code, switch 22 will route the call over
trunk 32 and provide signaling to switch 28 via trunk 32
requesting that switch 28 provide primary call origination
services. This signaling which will be communicated on trunk
32 can be in the form of a network specific facility (NSF)
parameter within the signaling system 7 (SS7) call setup
message. It will be understood by those skilled in the art
that although the SS7 signaling is utilized in this example,
other types of signaling which can convey this request to
switch 28 can be utilized. The NSF parameter will convey to
switch 28 that the call request is for primary call origination
services and that the provider of the services is to be 288,
i.e. AT&T. Switch 28 then queries SCP 34 database with parameter
information designating AT&T as the service provider, as well
as including the calling party number, also known as automatic
number identification (ANI), abbreviated called digits, and any
other necessary information for the query.

In a second example, trunk 32 is a private trunk. Suppose
trunk 32 is a dedicated trunk used only for traffic from local
subscribers who subscribe to AT&T for their local service. (AT&T is
one of the IXC switch 28 providers of primary call origination (e.g.
local) services.) Then IXC switch 28 when receiving a call over
trunk 32 will know the originator to be an AT&T service subscriber
and to query the SCP 34 database with parameter information
designating AT&T as the
service provider. Again, any other necessary information will be
included in the SCP query, such as the calling party number and the
abbreviated called digits.

In this case, subscriber 24 may dial an access code, such as
"*8", followed by the abbreviated digits for the called party. Note
that the *8 could be automatically generated or prefixed by the
Centrex 26 custom dial plan, and thus does not necessarily have to
be dialed by subscriber 24. If "*8" is automatically transmitted,
subscriber 24 just dials the abbreviated digits for subscriber 12.
The access code "*8" serves to cause Centrex 26 and central office
switch 22 to route the call over trunk 32. Since trunk 32 is
dedicated, IXC switch 28 will have predetermined instructions on how
to handle the call as described above.

The IXC switch 28 retrieves the records associated with
subscribers 24 and 12, compares the MBGID of subscribers 24 and 12,
and determines that both the calling and called party are members of
the same business group, namely, MBGID=10. In accordance with the
illustrative example, calling party 24 is permitted to only make
calls via switch 28 to members of its MBG since it has a semi-restricted
origination (SRO) parameter. Since subscriber 12 is a
member of the same MBG, the call origination screening by IXC switch
28 is satisfied. The switch 28 also conducts a call termination
screening using the "_RT" parameters. In this example, subscriber
12 has an unrestricted terminating parameter (URT). Thus, the call
terminating screening is passed (satisfied) since all calls via
switch 28 are permitted to terminate at subscriber 12.

With regard to Call Scenario #1, it will be noted that the
data stored as records in SCP database 34 for subscribers 24 and 12
constitute "complete" profiles for these end user subscribers. The
complete profile means having all of the information for the
subscribers that would be provided if the subscriber was directly
connected by a local loop/line to the switch 28 instead of being
connected by a trunk. This complete profile information allows
switch 28 to simulate a loop/line origination from a higher position
in the network hierarchy than the central office switch which
directly supports the subscriber. As used herein, a switch at a
higher hierarchical level refers to a switch closer to the toll
network than another switch, i.e. a level further from the
requesting subscriber. The IXC switch 28, in addition to serving as
a toll switch gateway or edge switch, also functions as a primary
call origination switch. The availability of complete profiles of
the subscribers in LATA 10 and the superior hierarchical position in
the network permits switch 28 to provide enhanced features and call
origination functions to subscribers in LATA 10 beyond the
conventional features provided by the central office switches and
PBXs in LATA 10. Since the IXC switch 28 has a complete profile, it
also has knowledge of signals which are relevant to each subscriber;
for example, a flash-hook signal initiated by subscriber 24 (or an
equivalent ISDN/SS7 representation for a 3-Way conference request if
the originator utilizes an ISDN telephone) which was received by IXC
switch 28 would be ignored since it has no meaning, that is, no
features associated with subscriber 24 require a flash-hook signal.

In the case where subscriber 20 originates a call to
subscriber 12, since subscriber 20 is not part of a Centrex, e.g.
Centrex 26, subscriber 20 may dial *10288 + "called-digits" in order
to place a call to subscriber 12. The "called-digits" would be
a number that SCP 34 could translate into the "true" number of
subscriber 12, this number being usable by IXC switch 28 and central
office switch 16 for routing the call. Alternatively, subscriber 20
may not even have to dial the *10288 if it has been provisioned as a
preferred primary service provider for subscriber 20 on central
office switch 22. Central office switch 22 will then automatically
process the call as if the subscriber had dialed the *10288, or
whatever access code that
would route the call to IXC switch 28 for primary call origination
services.

The process of handling a call from PBX supported subscriber
12 to Centrex supported subscriber 24 would follow similar steps.
Subscriber 12 would first dial an escape code to obtain a dial tone
from central office switch 16. Next, subscriber 12 would dial a
further escape code that would cause central office switch 16 to
route the call over trunk group 30 with a request for primary call
origination services from IXC switch 28. The number of the called
party would then be entered either as a complete directory number or
an abbreviated dialing plan if such a feature is supported by IXC
switch 28. The continuing processing by switch 28 would generally
follow that described above with access of information from SCP
database 34, call screening, and call termination to the called
party if allowed.

Thus, call origination services and features can be provided
by an IXC switch for calls originating via a PBX to a Centrex
supported subscriber and for calls originating via Centrex equipment
to a PBX supported subscriber.

Call Scenario #2

In this example, a person uses CPE 24 to place a call
utilizing IXC switch 28 to subscriber 12. This scenario is similar
to Scenario #1 except that the call originating person is a PIN
user, i.e. see subscriber PIN(X) in Table 1. The call originating
person (COP) invokes the call using CPE 24 the same way as explained
in Scenario #1 except that the COP enters PIN(X) before entering the
abbreviated number for subscriber 12. In this example, the COP's PIN
is 998877665. It will be apparent to those skilled in the art that
a special code or designator such as the "*" or "#" can be utilized
to identify the beginning, end or both of the PIN. The use of the
PIN permits IXC switch 28 to identify the COP and utilize the
features associated with the COP's record stored in SCP database 34
as identified by the PIN. In this example, the COP is a member of
the MBGID of 10 and is also permitted to use 3-way calling as
indicated in the features associated with PIN(X) as shown in Table
1.

In accordance with this illustrative example, IXC switch 28
utilizes the features associated with the PIN of the COP as opposed
to the features associated with the directory number of the
originating CPE 24 which was sent to the switch as part of the call
setup request. However, it is also envisioned that the features
associated with the COP and CPE 24 can both be retrieved by IXC
switch 28 and effectively OR'ed to yield the equivalent of all
features allowed to either the COP associated with the PIN or the
features associated with the CPE 24. This alternative arrangement
could be utilized to provide add-on features for people by
associating additional features with an assigned PIN.

The call setup from the COP utilizing CPE 24 to subscriber 12
is accomplished substantially the same as indicated in Scenario #1
except that the IXC switch 28 retrieves from SCP database 34 the
record associated with the PIN (or both the PIN and subscriber 24
records in accordance with the alternative embodiment). The call is
then completed via central office switch 16 and PBX 14 to subscriber
12.

In accordance with this illustrative example, the COP desires
to add to the existing call a third party, subscriber 20, which is
not a member of the business group. The COP is authorized to
originate calls to other than business group members since the COP
has an unrestricted origination (URO) feature as defined by the
PIN(X) record in SCP database 34 (see Table 1). Although subscriber
24 has an SRO feature, as opposed to the URO feature of the COP, the
less restrictive URO feature associated with the COP is utilized,
thereby permitting call origination outside the business group.

To initiate a 3-way call, the COP, during the established call
with subscriber 12, indicates a request for the 3-way call by a
flash-hook signal which is passed (e.g. as its equivalent ISDN/SS7
representation for a 3-Way conference request) to IXC switch 28.
Since a flash-hook is meaningful with regard to a 3-way feature, and
the 3-way feature is an assigned parameter in the record for the
COP, the switch 28 responds by putting subscriber 12 on hold and
provides dial tone to the COP. The COP enters the directory number
for subscriber 20. Upon collecting the directory digits transmitted
by the COP, the IXC switch 28 transmits a query to the SCP database
34 seeking information, i.e. a record, corresponding to the entered
directory number. Although subscriber 20 is not a member of any
business group, the COP has an URO parameter and hence, call
origination screening provided by switch 28 is satisfied. The
switch 28 then proceeds to transmit a call initiation request to
central office switch 22 requesting a call be set up with subscriber
20. A communication link is then established between the COP at CPE
24 and the subscriber 20. The entry of another flash-hook signal by
the COP at CPE 24 is transmitted to IXC switch 28 which interprets
the second flash-hook as a request to complete the 3-way conference.
The switch 28 then releases the "held" call path to subscriber 12.
Thus, the COP is in simultaneous communication with subscriber 20
and subscriber 12. It will be apparent to those skilled in the art
that the conference circuit needed to satisfy the 3-way call
requirements is provided by IXC switch 28 since this switch provides
the 3-way call service for such calls. As an alternate to the IXC
switch 28 directly providing the 3-way call requirements, the IXC
switch could direct (command) switch 22 to set up the 3-way call and
pass all needed parameters and data to switch 22.

This call scenario illustrates that a subscriber can utilize a
PIN to gain access to a predetermined set of call features that
differ from those features assigned to the line being used to
originate the call. This permits a member of a group to make calls
to other members of the group from a CPE without predetermined group
affiliation and without predetermined call features. This allows a
group member to retain those call features normally available to
members.

Call Scenario #3

In this example, a call originating person (COP) places an
interLATA call origination at CPE 20 to subscriber 64. In
accordance with the present invention, IXC switch 28 provides
primary call processing for the call originating in LATA 10 for a
terminating party located in LATA 54.

The beginning of this call is similar to that discussed in
call scenario #2 in that the COP utilizes a CPE (CPE 20) to request
service from IXC switch 28 via central office switch 22 and trunk
32. The COP enters his PIN (PIN(X) followed by subscriber 64's
abbreviated BG number 8-1234. The IXC switch 28 utilizes the PIN to
retrieve the corresponding record from SCP database 34 which is
stored in the IXC switch and used during the processing of the call.
As will be seen from the subscriber record associated with PIN(X) in
Table 1, the COP is associated with business group MBGID=10. The
abbreviated BG number entered by the COP for subscriber 64, namely
8-1234, may not find an SCP 34 database record with features and CPE
information for subscriber 64 since subscriber 64 is not known in
LATA 10. However, an SCP 34 database record will be found that
allows translation of 8-1234 to a public routing number; the public
routing number will be returned in the query response from SCP 34 to
IXC switch 28. Such a translation record could be part of a table
stored in SCP database 34 in which each row contains a MGBID group
number, a prefix or access code (e.g. "8" in abbreviated number 8-1234),
and an area code (e.g. 214) and office code (e.g. 568)
corresponding to the prefix code. Thus, a public routing number can
be derived based on the record corresponding to the MGBID group
number and access code.

IXC switch 28 will use the public routing number to route the
call through the toll network to IXC switch 48. The originally
dialed abbreviated number, 8-1234, will be preserved in some SS7
parameter, e.g. the access transport parameter (ATP), for use at IXC
switch 48. The COP is granted permission to complete the interLATA
MBG call to IXC switch 48 since no terminating screening can be done
at this time at IXC switch 28. The PIN(X) subscriber's URO
restriction will be carried in the SS7 BG parameter to IXC switch 48
where originating and terminating screening will be done for the MBG
call. Using the public routing number returned from SCP 34, IXC
switch 28 and toll switches 38 ... 40 route the call to the
terminating IXC switch 48. However, IXC switch 28 includes
additional information in the call setup message sent on the SS7
trunk 42 to toll switch 38 that includes the BG parameter indicating
the business group, originating restrictions, terminating
restriction of the calling party, an NSF parameter (also called
hierarchical parameter herein) indicating that hierarchical services
by the IXC switch(es) are to be provided for the call, and an ATP
that contains the originally dialed abbreviated number. These
pieces of information are in addition to other conventional call
setup message information which will be forwarded in a conventional
manner. The called party number, which is actually the public
routing number used to route the call to IXC switch 48, addresses
IXC switch 48. This indicates to IXC switch 48 that switch 48 is
the terminating IXC switch for this call. The called number is
received at IXC switch 48 along with the NSF and BG parameters, and
the ATP which carries the abbreviated number for subscriber 64. IXC
switch 48 interprets this information as requiring a query of SCP
database 50 for information concerning the abbreviated called party
number (subscriber 64). This query is made in order to provide both
call origination and termination screening.

If the screening process permits the call, the IXC switch 48
forwards the required setup information to the associated central
office switch which processes the termination of the call to the
desired party. However, if the screening process fails, i.e. it is
determined that the terminating party is not permitted to receive
the call request, the IXC switch gives the call originator
appropriate terminating error treatment, e.g. playing an error
announcement to the call originator.

Referring to Table 1, the record associated with "214-568-1234",
i.e. subscriber 64, is retrieved from SCP database 50. This
data identifies the subscriber as being a member of business group
10 and that the subscriber is SRT, meaning that the subscriber can
receive calls via an IXC switch only from a business group member.
However, since the COP is also a member of the same business group,
the call passes terminating screening. Since the originating
restrictions for the COP are URO (carried in the SS7 BG parameter),
the call passes call originating restrictions as well. Having
passed call origination and call termination restrictions, the call
is further advanced by the IXC 48 transmitting a call setup message
to central office switch 56 and associated Centrex equipment 62
which completes the call to subscriber 64.

In accordance with this call scenario, the IXC switches 28 and
48 support independent call origination screening and call
termination screening. A subscriber can utilize a PIN to gain
access to a predetermined set of call features for an interLATA
call. This permits a member of a group to make calls to other
members of the group from a CPE in another LATA and retain those
features normally available to the members.

Call Scenario #4

In this example a subscriber 12 of PBX 14 places an interLATA
call to subscriber 64 of Centrex services 62. Subscriber 12 dials
some access code and the called number, e.g. *10 - xxx - 7/10
digits. The xxx is the carrier ID (CIC) or service provider located
at IXC switch 28 from whom subscriber 12 wishes to obtain
originating services. The *10-xxx is a signal (access code) to the
local CO switch 16 that this call is requesting "originating
services" from the "xxx" service provider (e.g. AT&T or MCI) at IXC
switch 28. CO switch 16 routes the call over trunk 30 applying the
appropriate signaling to let IXC switch 28 know that this is a call
request for originating services. Such signaling to IXC switch 28
could be as simple as the call coming in over a "dedicated" trunk
30, or having received an SS7 network specific facility (NSF)
parameter for said service. It will also be understood that an
abbreviated dialing plan could be used to identify the called party
instead of the 7/10 digit called party number since the originating
party will normally have abbreviated dialing as a supported PBX
feature.

Upon receiving the call and signaling, IXC switch 28 is
programmed to query the SCP 34 database for the appropriate "xxx"
(Carrier ID or CIC) for subscriber 12. Subscriber 12's ANI (calling
party number) is also used at the IXC switch 28 for billing the
call. IXC switch 28 is programmed to query the SCP 34 database for
the appropriate service provider "xxx" to obtain the calling party's
information, e.g. information defining their allowed features and
assigned terminal equipment. The retrieved information from SCP 34
identifies subscriber 12 as being a member of business group 10 with
URO and URT features; Table 1 shows the defined features. SCP 34
also provides the public routing number to IXC switch 28 so that the
call can be routed to IXC switch 48. Alternatively, an SCP database
which is dedicated to one service provider would not require a query
to locate the service provider since the carrier in this case could
be assumed.

SS7 signaling to IXC switch 48 includes information (e.g. an
SS7 NSF parameter) identifying the call as one having requested
originating services from an IXC switch. Additionally, the SS7
signaling conveys the business group affiliation and the origination
and termination restrictions associated with subscriber 12. This
serves to cause IXC switch 48 to query its SCP 50 database before
terminating the call to a local network, e.g. to trunk 58. IXC
switch 48 retrieves information from SCP 50 on the called party 64,
e.g. subscriber 64's restrictions, if any. If IXC switch 48 and SCP
50 determine that the call can be allowed to complete, the call is
advanced to CO switch 56 which completes the call to subscriber 64.
In this instance, the call is allowed to complete. Although
subscriber 64 has an SRT restriction, it is satisfied since
subscriber 12 has the same business group affiliation.

In this example, a PBX subscriber is allowed to use enhanced
features even while making an interLATA call to a Centrex subscriber
of the same business group affiliation. Thus, neither the interLATA
nature of the call nor the mix of PBX and Centrex supported
subscribers inhibited the use of enhanced features.

General Information

The above examples illustrate that enhanced subscriber
features need not be restricted by limitations associated with the
calling party's equipment (PBX or Centrex) or local central office
capabilities. An important aspect of this invention resides in
recognizing and solving the problems which prevented members of
affiliated groups from utilizing enhanced features that were
available within their local equipment/LATA community when making
calls to other members of the group served by different types of
equipment or located in different LATAs.

It will be apparent that other variations of the uses of the
above embodiments of the present invention can be made. For
example, a 1-800-xxx-yyyy number could be used in place of an access
code as a way of conveying a request to an IXC switch for call
origination support. The IXC switch would receive this call request
from a local central office and, after querying its associated SCP
database, would recognize the 800 call request in combination with
the calling party number as a request for call origination support.
In another aspect, a single setup message, which could be equivalent
to a series of signals, could be received by the IXC switch
containing all required signals and information needed to permit
call origination services to be provided to a requesting subscriber.

In view of the above descriptions of embodiments, it will be
apparent that other call scenarios are supported by this invention.
For example, a subscriber 12 of PBX 14 in LATA 10 can utilize call
origination services, such as abbreviated dialing, membership-based
call screening, 3-way conferencing, etc., provided by IXC switches
28 and 48 when calling a subscriber 74 of PBX 70 in LATA 54.
Similarly, Centrex subscriber 24 served by a local switch 22 in LATA
10 can utilize call origination services provided by IXC switches 28
and 48 when calling a Centrex subscriber 64 served by local switch
56 in LATA 54. Thus, call origination services from an IXC switch
can support PBX to PBX, PBX to Centrex, Centrex to PBX, and Centrex
to Centrex calls as well as calls not supported by either PBX or
Centrex services.

Although embodiments of the invention have been described
above, the scope of the invention is defined by the claims which
follow.

Subscriber

Features

CPE Type

24

IDP1

Analog DTMF

TGSR:

312-713-1234

TGID=05

SRO

URT

MBG:

MBGID=10

12

IDP1

Custom ISDN

TGSR:

708-979-1234

TGID=06

URO

URT

MBG:

MBGID=10

20

Null

Analog DTMF

312-713-1235

PIN (X)

IDP1

Null

MBG:

998-877-665

MBGID=10

URO

URT

3-WAY

64

IDP1

N-ISDN

TGSR:

214-568-1234

TGID=15

SRO

SRT

MBG:

MBGID=10

60

Null

Analog DTMF

214-568-7981

74

IDP1

Analog DTMF

TGSR:

214-979-3535

TGID=12

URO

URT

MBG:

MBGID=10

Claims (8)

A method for controlling features made available to a
subscriber comprising the steps of:

recognizing a request for call origination by a
calling party on an associated communication line;

locating a first record in a database based on the
identification of the calling party's line;

determining a first set of predetermined call features
based on information contained in the first record; characterized by the steps of:

receiving a personal identification number (PIN)
entered by the calling party via said associated communication line;

locating a second record based on the PIN in the
database, said second record independent of said first record;

determining a second set of predetermined call
features based on information contained in the second record;

determining a third set of call features that is made
available to the calling party based on call features contained in
said first and second sets of features, whereby call features
associated with a particular line can be supplemented by other call
features associated with the PIN of a particular subscriber.

The method according to claim 1 wherein said
determining of the third set of call features comprises selecting
all call features found in any of the first and second sets of
features.

The method according to claim 1 wherein said
determining of the third set of call features comprises selecting
only the call features contained in the second set of call features.

The method according to claim 1 further comprising the
steps of receiving a predetermined authorization code from the
calling party and validating said authorization code prior to making
any call features contained in the second set of call features
available to the calling party.

A telecommunication network that supports
subscribers, comprising:

means for recognizing a request for call origination
by a calling party on an associated communication line, the
recognizing means recognizing the request being for call origination
services;

means for locating a first record in a database based
on the identification of the calling party's line;

means for determining a first set of predetermined
call features based on information contained in the first record; characterized in that it comprises:

means for receiving a personal identification number
(PIN) entered by the calling party via said associated communication
line;

means for locating a second record based on the PIN in
the database, said second record independent of said first record;

means for determining a second set of predetermined
call features based on information contained in the second record;

means for determining a third set of call features
that is made available to the calling party based on call features
contained in said first and second sets of features, whereby call
features associated with a particular line can be supplemented by
other call features associated with the PIN of a particular
subscriber.

The network according to claim 5 wherein said means
for determining the third set of call features comprises means for
selecting all call features found in any of the first and second
sets of features.

The network according to claim 5 wherein said means
for determining the third set of call features comprises means for
selecting only the call features contained in the second set of call
features.

The network according to claim 5 further comprising
means for receiving a predetermined authorization code from the
calling party and means for validating said authorization code prior
to making any call features contained in the second set of call
features available to the calling party.

EP199603080231995-11-161996-11-05Control of call features provided to a subscriber by a hierarchical telecommunication switch
Expired - LifetimeEP0774874B1
(en)